A vapor compression system and method for operating the vapor compression system are provided. The vapor compression system includes a compressor, a condenser, and at least one check valve disposed between the compressor and the condenser. The method provides for the transmitting of a shutdown command to the compressor, the compressor including a rotating shaft and a magnetic bearing, the magnetic bearing having an active mode and an inactive mode, the magnetic bearing levitating the rotating shaft in the active mode. The method further provides for the maintaining of the magnetic bearing in the active mode during a minimum time period, the magnetic bearing switching from the active mode to the inactive mode after the minimum time period is reached.

A power converter includes: a rectifying and boosting unit that rectifies first alternating-current power supplied from a commercial power supply and boosts a voltage of the first alternating-current power; a capacitor connected to an output end of the rectifying and boosting unit; an inverter to convert power output from the rectifying and boosting unit and the capacitor into second alternating-current power, and output the second alternating-current power to a device; and a control unit that reduces a current flowing through the capacitor by controlling the rectifying and boosting unit and by controlling the inverter such that the inverter outputs, to the device, the second alternating-current power containing a ripple dependent on a ripple of power flowing from the rectifying and boosting unit into the capacitor. The control unit controls in accordance with a load state.

A motor drive apparatus includes a connection switching device that switches a connection state of windings of a first motor by switches; an inverter that applies an alternating-current voltage to the windings; a first control device that controls the inverter and the connection switching device; and a second control device that controls a second motor for an element that affects the first motor. Control by the first control device when switching includes a first stage of bringing an effective value of alternating current flowing through the windings close to zero compared to that before the connection state is switched; and a second stage of suspending output of the alternating-current voltage from the inverter. The second control device keeps the second motor running during the first and second stages, and the first control device switches the switches in the second stage.

An air conditioner is provided that reduces user discomfort due to vibrations and noises at a compressor, piping, and the like such as of an air conditioner. To achieve this, an air conditioner includes: a compressor (10) that has a motor (12) and a compression mechanism (14) driven by the motor (12); a speed detector (43) that detects a rotation speed of the motor (12); a drive mode controller (48) that controls a drive mode of the motor (12); and refrigerant piping that is connected to the compression mechanism (14) and allows a refrigerant to flow therethrough, wherein the drive mode controller (48), for stopping the motor (12), decelerates the motor (12) to a rotation speed equal to or lower than a resonance frequency between the compression mechanism (14) and the refrigerant piping.

There is disclosed a vehicle air-conditioning device in which a refrigerant subcool degree in a radiator is appropriately controlled, so that comfortable and efficient vehicle interior air conditioning is achievable. The vehicle air-conditioning device executes a heating mode in which a controller lets a refrigerant discharged from a compressor 2 radiate heat in a radiator 4, decompresses the refrigerant by which heat has been radiated by an outdoor expansion valve 6, and then lets the refrigerant absorb heat in an outdoor heat exchanger 7. In the heating mode, the vehicle air-conditioning device controls a refrigerant subcool degree SC of the radiator 4 by the outdoor expansion valve 6. On a basis of a radiator inlet air temperature THin that is a temperature of the air flowing into the radiator 4, the controller corrects a target subcool degree TGSC that is a target value of the refrigerant subcool degree SC in the radiator 4 in a lowering direction, as the radiator inlet air temperature THin rises.

A method of operating an air conditioning system including: operating a refrigerant compression device at a demand speed to circulate refrigerant through a refrigeration circuit; monitoring, using a temperature sensor, a temperature of external ambient air; monitoring, using a pressure sensor, a pressure of the refrigerant within the refrigerant circuit; detecting, using a controller, when the temperature of external ambient air is greater than a selected temperature; detecting, using the controller, when the pressure of the refrigerant is greater than a selected pressure; and reducing the speed of the refrigerant compression device to a selected speed for a first duration of time when the temperature of external ambient air is greater than the selected temperature and the pressure of the refrigerant is greater than the selected pressure.

A refrigeration appliance includes at least one warm storage compartment and one cold storage compartment and a refrigeration device having at least two mutually parallel evaporators connected in series with a compressor, a condenser, and a shut-off valve between the condenser and evaporators in a refrigerant circuit so that each evaporator cools one storage compartment. An operating method for the refrigeration appliance includes the steps a) deciding whether a need for cooling has newly occurred in the warm storage compartment, and, if so, b) operating the compressor while the shut-off valve is closed to cause refrigerant to back up in the condenser, c) opening the shut-off valve and supplying the evaporator of the warm storage compartment with the backed up refrigerant. In step b) the mass flow rate through the compressor is estimated and the time for performing step c) is determined by using the estimated mass flow rate.

Embodiments of the present disclosure relate to a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system that includes a refrigerant loop, a compressor disposed along the refrigerant loop and configured to circulate refrigerant through the refrigerant loop, and an evaporator disposed along the refrigerant loop and configured to place the refrigerant in thermal communication with a cooling fluid, where the refrigerant surrounds a tube bundle disposed in the evaporator, the tube bundle is configured to flow the cooling fluid, and the evaporator has a height based at least on a target height of a liquid level of refrigerant in the evaporator, the evaporator includes a discharge configured to direct the vapor refrigerant from the evaporator to an inlet of the compressor, and an interface between the discharge and the inlet is without a bend.

An automated refrigerant recharging system determines whether a cooling load parameter of a direct expansion (DX) cooling system that cools information technology (IT) modules of an information handling system (IHS) has reached a defined recharging threshold that results in a response of the pressure value for measurement by the pressure transducer. In response to the cooling load parameter being equal to or greater than the defined recharging threshold, a controller determines whether a pressure value of the refrigerant of the DX cooling system is less than a defined target pressure value corresponding to the defined recharging threshold. In response to determining that the pressure value of the refrigerant of the DX cooling system is less than the defined target pressure value, the controller autonomously opens a control valve to transfer refrigerant to the DX cooling system.

An apparatus and a method for detecting refrigerant leakage in an air source heat pump system. The method for detecting refrigerant leakage in an air source heat pump system includes the following steps in a cooling mode: S110: obtaining a running parameter of an air source heat pump system, wherein the running parameter at least includes a compressor rotational speed; S120: comparing the running parameter with a preset running parameter range; S130: updating a cumulative score when the running parameter falls within the preset running parameter range; and S140: when the cumulative score exceeds a predetermined cumulative score, determining that refrigerant leakage occurs, and when the cumulative score does not exceed the predetermined cumulative score, return to step S110.